RECENT WORK IN AGRICULTURAL SCIENCE. 



CHEMISTRY. 



Report of the chemical laboratory of the Ploti Agricultural Experiment 

 Station, B. M. Velbel {Six. Rap. An. Sta. Expt. Agron. Ploti, 1900, pp. 73-111, 

 315-234). — The work of this department of the station during the year inchided 

 chemical studies of atmospheric precipitation, lysimeter water, products from the 

 field experiments, and methods of analysis. It is a continuation of that of previous 

 years (E. S. R., 12, p. 916) and has for its i")rimary object a study of the evolution 

 of the combinations and the annual balance of nitrogen in the soil. This involves 

 the determination of the nitrogen brought down by precipitation, that lost in the 

 drainage water, and that taken up by the products grown on the soil. The ammonia, 

 nitrites, and nitrates in the atmospheric pi-ecipitation are reported. The lysimeters, 

 having the same surface area as the rain gauges, viz, 500 sq. cm., were so placed 

 as to collect drainage water to depths of 30 cm. (arable soil), 45 (arable and subarable 

 soil), and 1 meter (subsoil). The relative solubility of the soil constituents, as 

 shown by the analyses of the lysimeter waters, was (1) organic matter, (2) lime, 

 (3) nitrates, (4) sodium chlorid, (5) silica, (6) magnesia, (7) iron oxid and alumina, 

 (8) potassium chlorid, (9) phosphoric acid, and (10) sulphuric acid, i. e., organic 

 substances and combinations of lime and nitric acid, probably Ca(N03). 2, predomi- 

 nated in the humus-calcareous soils experimented with. The effect of plant cover 

 in reducing drainage losses was strikingly shown in these observations. The results 

 show such a rapid removal of organic matter, nitrogen, and mineral matter from the 

 arable layer (30 cm. deep) of the soil that impoverishment of the upper soil would 

 soon result if the losses were not replaced. The amount of these constituents carried 

 by the drainage water to a depih of 50 cm. was still quite large, but under the nor- 

 mal conditions obtaining in these observations the amount of drainage at 1 meter 

 depth was very small (25 cc. during the year). From data showing the amount of 

 combined nitrogen found in the drainage water during the year, it is estimateil that 

 one acre of the arable layer of the soil (to a depth of 30 cm.) yielded 21.125 lbs. of 

 nitric nitrogen, of the arable and subarable layers (to a depth of 45 cm.) 37.72 lbs. of 

 nitrogen. The rain, etc., which fell during the same period brought down 3.58 lbs. 

 per acre of nitrifiable nitrogen. Deducting this, it appears that the arable layer 

 pnxluced 17.55 lbs. per acre of ammoniacal and nitric nitrogen, and the arable and 

 subarable layers 34.14 lbs. per acre. 



A comparison of the nitrogen required by the products grown on the soil with that 

 brouglit down by rainfall, etc., shows the latter to be almost insignificant, and 

 emphasizes the importance of adopting a system of culture and cropping, especially 

 of green manuring, which will replace the losses which occur. 



A method for determining small quantities of carbonates, A. D. Hall and 

 E. J. Russell {Jour. Chem. Soc. ILondon], 81 {1902), No. 470, pp. 8t-S5,fig. 1).— 

 Methods employing Scheibler's apparatus are stated to be inaccurate for substances 

 such as soils containing as little as 0.5 per cent of calcium carbonate, due to the solu- 



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